An interesting pattern of ship condensation trails ("ship tracks") within the extensive marine layer stratocumulus cloud deck was revealed by NOAA GOES-10 (above) and GOES-12 (below) imagery over the northern East Pacific Ocean on 10 February 2003. Particles in the exhaust plumes of ships tend to act as cloud condensation nuclei (CCN), creating streaks consisting of smaller cloud droplets within the pre-existing cloud deck. The resuling changes in the emissivity of the marine layer stratocumulus are easily detected using the 3.9 micrometer (shortwave) IR channel data. The ship tracks exhibit a colder 3.9 micrometer InfraRed (IR) brightness temperature at night (above, darker blue enhancement), while during daylight hours these features exhibit a warmer brightness temperature (below, darker gray enhancement) due to this channel's sensitivity to the component of reflected sunlight.
The ship track cloud features are somewhat apparent in the GOES-12 visible imagery, though their detection is more positive using the 3.9 micrometer IR channel. The ship tracks are not detectable using the standard 10.7 micrometer longwave IR channel.
Fade between GOES-12 visible and 3.9um IR channel images